Each year a number of children die because they are left in vehicles for a prolonged period of time. These tragic incidents typically arise when a driver reaches her destination and leaves the car to run a quick errand, forgetting the child is in the car. Infants are particularly susceptible to dehydration and may relatively quickly slip into a comatose state or even worse, suffer a deadly heat stroke.
A number of car-seat safety devices have been developed to address the above identified problem. One system for preventing children from becoming inadvertently locked within a vehicle is described in U.S. Pat. No. 5,793,291. The '291 patent describes activating an alarm when motion is detected and the temperature is above a threshold level. The system utilizes a motion detector to detect the presence of a child or pet within a vehicle. Although this system provides some advantages, particularly in the case of older children that may inadvertently lock themselves in a vehicle while playing and may be actively seeking escape, it fails to protect infants who have been left asleep in their child seats and are not capable of sufficient activity to set off a motion detector. Infants, for example, may become dehydrated during sleep and may drift into a comatose state without ever waking or moving.
Another patent, U.S. Pat. No. 6,104,293, describes an apparatus for warning when a child has been left in an infant seat and the vehicle has been turned off. The apparatus includes an occupant detection mechanism for detecting the presence of an occupant in an infant seat located within a vehicle; an ignition detection mechanism for detecting the state of the vehicle's ignition system; a control unit for generating an alarm signal when the occupant detection mechanism detects the presence of an occupant within the infant seat and the ignition detection mechanism detects that the vehicle's ignition system has been turned from an “on” state to an “off” state; and an alarm unit for generating an alarm in response to the alarm signal. See also U.S. Pat. No. 5,949,340.
U.S. Pat. No. 6,489,889 describes a system that activates an indicator when the seat belt is buckled and the ignition is turned off. The system includes a controller that controls the indicator in response to the seat belt buckled signal and the ignition-off signal. Various types of indicators are described including remote keyless devices as well as cellular networks.
NASA has also developed a child presence sensor driver alarm. As described, a driver alarm, designed to hang on the driver's key ring, sounds ten warning beeps if the driver moves too far away from the vehicle. If the driver doesn't return within one minute, the alarm will beep continuously and cannot be turned off until it is reset by returning to the child safety seat. The sensor switch triggers immediately when a child is placed in the seat and deactivates when the child is removed. The sensor detects weight once the child is placed in the seat, transmitting a unique code to the driver-alarm module via a radio-frequency link. If the driver moves too far from the vehicle, the alarm sounds. See NASA News Release No. 02-008, Langley Research Center (Feb. 5, 2002).
The above described systems, however, tend to be overly complicated. A simpler and more elegant solution is still desirable. None of the above described systems alert a driver that her child is left in the car as taught herein.